Reversible rotary pump



July 11, 1967 SEIJI YAMANE 3,330,215

REVERS IBLE ROTARY PUMP Filed Sept. 10, 1965 2 Sheets-Sheet l INVENTOR. $611! YAMJ/ July 11, 1967 5E|J| YAMANE 3,330,215

REVERS I BLE ROTARY PUMP Filed Sept. 10, 1965 2 Sheets-Sheet 2 INVENTOR. saw y/mA NE A Tran/r ys United States Patent 3,330,215 REVERSIBLE ROTARY PUMP Seiji Yamane, 1214 S-chome, Hatanodai, Shinagawa-ku, Tokyo-to, Japan Filed Sept. 10, 1965, Ser. No. 486,370 4 Claims. (Cl. 103143) This invention relates to a reversible rotary pump having special small rotors mounted on a larger rotor and a casing the inner surface of which is for-med by utilizing loci generated on a circle by the rotating small rotors.

An object of the present invention is to provide a rotary pump in which suction and discharge of fluid at the inlets and outlets can be determined depending on the rotating direction of the pump.

Another object of the invention is to provide a rotary pump in which volume of discharge is kept constant with out pulsating and generating bubbles.

A further object of the invention is to provide a rotary pump which can operate as a power transmission means by feeding, reversibly, external compressed fluid to the pump.

A further object of the invention is to provide a rotary pump in which suction chambers and discharge chambers can be partitioned or sealed tightly without packings.

A further object of the invention is to provide a rotary pump of very large pumping capacity, high pressure, small size and light weight.

In order to attain these objects, the rotary pump according to the invention comprises a pump casing, a substantially circular relatively large rotor within said casing having a sliding fit therewith at least at a portion of the inner surface of said casing, and at least two small rotors rotably mounted on said large rotor and rotating in an integral ratio thereto. The inner surface of said casing is formed utilizing loci generated by an arbitrary point on the circumference of said small rotors while the contour of said small rotors is such that said small rotors may move in sliding and/or rolling contact with the inner surface of said casing while rotating about their own axes. An inlet and an outlet are provided, respectively at opposite sides of said sliding fit portion of the casing with said large rotor, said inlet and outlet leading to the spaces between said casing and said rotors separated by said sliding fit portion respectively.

Other objects and advantages will be more apparent from the following description and accompanying drawings and in which FIGS. 1(A) and (B) are diagrams for explaining the principle of one embodiment of the invention,

FIGS. 1(C) and (D) are diagrams for explaining the principle of another embodiment of the invention,

FIG. 2(A) is a cross section view of a rotary pump embodying this invention,

FIG. 2(B) is a fragmentary view along the line M-M in FIG. 2(A),

FIG. 3 is a longitudinal section view of the pump in FIG. 1,

FIGS. 4(A) to (F) are cross section views similar to that of FIG. 2(A) showing different operating situations,

FIG. 5 is a cross section view showing a gear mechanism of the rotary pump,

FIG. 6 is a cross section view showing a modified construction,

3,330,215 Patented July 11, 1967 FIG. 7 is a cross section view showing other modified construction,

FIG. 8 is a cross section view showing a further modifled construction, and

FIG. 9 is a longitudinal section modification.

In FIG. 1(A), on the circumference of a circle & having a radius R and a center at O is positioned the center point 0 of a circle having a radius R which touches internally a circle concentric with the circle Namely, R equals R +R The center point 0 of the circle lies on the diameter Y -O -Y of the circle as shown. Now, suppose that the circle p begins to roll along the inside of the circle 1 in the direction shown by an arrow u while rotating about its own center in the direction shown by an arrow u a point P on the periphery of the circle generates a locus 1 passing through Y X, and Y Similarly a locus 1 may be obtained by the circle rolling and rotating in the reverse direction. Here X and X are intersection points of a circle having a radius R and loci l and As an example, the relation between rotation of the circle and movement of its center 0 along the circle may be selected to be such that the circle rotates in the direction M1 about its center while the center point 0 rotates about the center 0 of the circle 5 in the direction u When the point 0 moves around the center 0 by an angle a to a point 0 the point P also moves around the center of the circle e by the angle a to a point P. p is the intersection point of the locus 1 and the line passing through 0 and 0 Such intersection points in the range from 11:0 to oc= generate a locus 1 within the circle 5 as shown in FIG. 1(3). Similarly a locus 1 is obtained in the range from =90 to oc=l30. On the other hand, the range of the circular are having the radius R in FIG. 1(B) corresponds to that of the circular arc having the radius R, in FIG. 1(A). Finally, if a cam-shaped disc, having an upper curved half 1 4 and a lower circular half with the radius R moves along the circle while rotating about the center 0 the cam-shaped disc may be kept in sliding contact, at a point, with the inside of an outer circumference having an upper curved half -1 and a lower circular half with the radius R Next, relation between rotation of the circle and movement of its center 0 along the circumference of the circle 5 may be also selected to be such that the circle gb rotates in the direction 11 about its center as shown in FIG. 1(C), that is, in the opposite direction to that 11 in FIG. 1(A) while the center point 0 rotates about the center 0 along the circle in the direction a When the point 0 moves around the center 0 by an angle on to a point 0 the point p on the circumference of the circle at the angle at to the line Y O moves around the center of the circle by the angle a to a point p Then the point lies on the line passing through 0 and 0 Further, with movement of the point 0 to a point 0 the point p moves to a point at the same angle a to the line Y -O parallel to the line Y O Thus a locus 1 passing p and X is obtained by the point p on the circumference of the circle moving along the circumference of the circle while rotating about its center. Namely, the point p on the circle contacts the locus 1 while keeping always at the constant angle a to the Y -Y axis. Similarly the view showing a further 3 point p symmetrical to the point generates a locu l passing through X p thus generate an arc intersecting the circle A concave curve 1 within the circle is given, in that the points X and X cut the circle e moving along the circle while rotating about its center.

In FIGS. 2 and 3, 1 designates a pump casing, the inner surface of which corresponds to the outer circumference having the upper curved half l l and the lower circular half with the radius R, in FIG. 1(A). The inner surface in the region between X, and X is a circular arc having the radius R in FIG. 1(A). Within the casing 1, a large rotor 2 is mounted fixedly on a main shaft 6. A pair of inscri-bing small rotors 3 and 3, corresponding to a camshaped disc having upper curved half I 4 and the lower circular half with the radius R in FIG. 1(B), are rotably supported by means of shafts 5 and 5 symmetrically with respect to the main shaft 6 on the rotor 2. The space between the casing 1 and the rotor 2 forms enclosed chambers with a front cover 9 and a part of rotor 2 serving asa rear 'cover.

The surface or side of the large rotor 2 facing the front cover 9 has a radius corresponding to R in FIG. 1(A), while the portion serving as the rear cover thereof is made capable of rotating in sliding contact with the casing 1.

The shafts 5, 5' carrying the small rotors 3, 3 pass through the rear cover portion of the rotor 2 and are secured to planetary gears 13, '11. These planetary gears 13, 11 mesh with a sun gear 12 fixed to a rear plate having a bearing for the main shaft 6. The rear plate 10 is secured to the casing 1 by means of bolts 15. 7 and 8 denote an inlet and an outlet provided in the casing 1 at opposite sides of the sliding fit region X -X thereof with the rotor 2. When the main shaft 6 rotates, the rotor 2 also rotates, and the planetary gears 13 and 11, coaxial with the small rotors 3 and 3', revolve around the sun gear 12 while rotating about their axes. Thus the space within the casing 1 is divided by the rear cover portion of the rotor 2 into a gear chamber and a pump chamber in which the small rotors 3, 3 turn with the large rotor 2 while about rotating their own axes in sliding contact with the casing 1. Further, the rotor 2 intercepts the pump chamber in the region X X and divides the casing into two .parts, one on each side of said region.

The operation of the pump is shown in FIG. 4. In FIG. 4(A), the upper small rotor 3' is on the midpoint of the inner surface curve of the casing 1, and touches the circular arc portion capable of contacting the rotor 2.'The

small rotor 3- turns with the rotor 2 while rotating its own axis in the direction as shown. Contact points of the small rotor 3' are always on the inner surface of the casing 1. With rotation the lower small rotor 3 compresses fluids within a compartment E and discharges it through the outlet 7 (see FIGS. 4(A)-(D)). At the same time, suction of new fluid through the inlet 8 is carried out. Either the small rotor 3' or the rotor 2 continues to touch the circular arc portion X X of the inner surface of the casing to divide the pump chamber, and therefore ,makes easy compression of the fluid in the compartment E by the small rotor 3. a

. In a position as shown in FIG. 4(E), the compression stroke bythe small rotor 3 ends and'the compression stroke by the other small rotor 3' begins. Namely, the fluid within a compartment D may flow through an escape slot 4 (see FIG. 2) to the outlet 7. 'Thus the small rotors 3 and 3' carry out alternately compression and suction in. each half rotation of the rotor 2.

Suppose that the pumping stroke is carried out in the regionof the lower circular half concentric with the rotor 2 of the casing, the actions of small rotors 3 and 3 maintain a'balance between suction and compression, so that discharged volume of the fluid is always constant and not pulsates.

FIGS. 5 and 6 illustrate the embodiment according to the principle shown in FIGS. 1(C) and (D). In FIG.

In FIG. 1(D) the points p and 5, the planetary gears 17 are used as intermediate gears interposed between the sun gear 12 and the gears 13 for rotating the small rotors 3, 3'. The intermediate gears 17 are rotably mounted by means of shafts 16 on the rear cover portion of the rotor 2. The small rotors 3, 3 are carried on the shafts 5 of the gears 13 passing through the rear cover .portion of the rotor. Here the gear ratio of the sun gear 12 to the gears 13 is selected as 1:1. The rotating direction of the small rotors 3, 3' is opposite to that of the rotor 2. The small rotors 3, 3 have a recess corresponding to the concave curve I as shown in FIG. 1(D). Since the rotating directions of the small rotors 3, 3 and the rotor 2 are opposite to each other, the rotors 3, 3 rnove in sliding and rolling contact with the inner surface of the casing 1. There is only one intercepting portion partitioning the pumping chamber.

In the embodiment shown in FIG. 7, the gear ratio of the sun gear to the gears for rotating the small rotors is selected as 2:1. In this embodiment, two pumping compartments are formed bytwo intercepting portions 19 and 19. The small rotorsm-ove in sliding and partly rolling contact with the inner surface of the casing 1.

In FIG. 8, the gear ratio of the'sun gear to the gears for rotating the small rotors is selected as 3:1, and the lengths of the circumferences of the small rotors are selected as one third of that of the inner surface of the casing 1, so that the rotors may move in perfectly rolling contact with the inner surface of the casing. Three intercepting portions 20, 21, 22 are formed.

In FIG. 9, the rotor 2 serves notonlyas a rear cover portion but as a front cover portion in order to prevent the fluid in the pumping chamber from leaking. Small r-otors 3 are, therefore, rotably disposed between the front cover portion and the rear cover portion. 24 and 24'denote sliding surface of the rotor 2 and the casing 1. 23 is the inner surface of the casing 1 as described.

What I claim is:

1. A reversible rotary pump comprising, in combination, 'a casing; a substantially circular relatively large rotor; means rotatably mounting said rotor in said casing, said rotor having at least one-peripheral portion engaging at least one arcuate surface portion of the inner sur- 3 face of said casing; the inner surface of said casing and a peripheral surface of said rotor conjointly defining inlet and outlet chambers extending in opposite angular.

directions from each arcuate surface portion; at least two relatively small rotors rotatably mounted on said relatively large rotor within said casing; means interconnecting said large rotor and said small rotors for 1013- tion of said small rotors on said large rotor, as the latter rotates about its axis, at an angular velocity which has an integral ratio to the angular velocity of said large rotor; the inner surface of said casing being formed as the loci generated by arbitary points on the circumferences of said small rotors during rotation of said large in said large rotor and said small rotors rotate in opposite angular directions. V V

4. A reversible rotary pump, according to claim 1, wherein said casing has a circular inner surface axially adjacent said first mentioned inner surface thereof; said relatively large rotor having a pair of axially adjacent portions, one of which has a completely circular periphery in continuous sliding engagement with said second mentioned circular inner surface of said casing, and the.

other of which has said peripheral portion engaging at least one arcuate surface portion of the first mentioned inner surface of said casing; said small rotors being mounted in circular recesses in said second mentioned portion of said large rotor, said circular recesses opening outwardly through the periphery of said second mentioned portion of said large rotor.

References Cited UNITED STATES PATENTS 377,143 1/1888 Bullock 91--150 6 Mason 103-143 Roberts 1O3--143 Conklin 91150 Booth 103-143 Booth 103143 Allsup 103143 Marsh 103143 DONLEY J. STOCKING, Primary Examiner. 

1. A REVERSIBLE ROTARY PUMP COMPRISING, IN COMBINATION, A CASING; A SUBSTANTIALLY CIRCULAR RELATIVELY LARGE ROTOR; MEANS ROTATABLY MOUNTING SAID ROTOR IN SAID CASING, SAID ROTOR HAVING AT LEAST ONE PERIPHERAL PORTION ENGAGING AT LEAST ONE ARCUATE SURFACE PORTION OF THE INNER SURFACE OF SAID CASING; THE INNER SURFACE OF SAID CASING AND A PERIPHERAL SURFACE OF SAID ROTOR CONJOINTLY DEFINING INLET AND OUTLET CHAMBERS EXTENDING IN OPPOSITE ANGULAR DIRECTIONS FROM EACH ARCUATE SURFACE PORTION; AT LEAST TWO RELATIVELY SMALL ROTORS ROTATABLY MOUNTED ON SAID RELATIVELY LARGE ROTOR WITHIN SAID CASING; MEANS INTERCONNECTING SAID LARGE ROTOR AND SAID SMALL ROTORS FOR ROTATION OF SAID SMALL ROTORS ON SAID LARGE ROTOR, AS THE LATTER ROTATES ABOUT ITS AXIS, AT AN ANGULAR VELOCITY WHICH HAS AN INTEGRAL RATIO TO THE ANGULAR VELOCITY OF SAID LARGE ROTOR; THE INNER SURFACE OF SAID CASING BEING FORMED AS THE LOCI GENERATED BY ARBITARY POINTS ON THE CIRCUMFERENCES OF SAID SMALL ROTORS DURING ROTATION OF SAID LARGE ROTOR; THE PERIPHERAL CONTOURS OF SAID SMALL ROTORS HAVING A CONFIGURATION SUCH THAT SAID SMALL ROTORS ROTATE IN CONTINUOUS CONTACT WITH THE INNER SURFACE OF SAID CASING DURING ROTATION OF SAID LARGE ROTOR; A FLUID INLET PORT IN COMMUNICATION WITH SAID INLET CHAMBER; AND A FLUID OUTLET PORT IN COMMUNICATION WITH SAID OUTLET CHAMBER. 